There is known a volume rendering (VR) technique, i.e., a process of reconstructing a medical image taken by an image diagnostic apparatus into volume image data and displaying the volume image data as a 2D image on a monitor. Display of such a volume image as a 3D image is also contemplated for giving a real sense of depth to the volume image. It is expected that display of a medical image as a 3D image is applied to various situations, such as a conference before a surgical operation, a simulation of an operation plan, and intra-operative navigation.
A monitor which allows stereoscopic viewing of two parallax images (binocular parallax images) taken from two viewpoints with use of dedicated equipment, such as glasses for stereoscopic vision, has been in practical use. Additionally, a monitor which allows naked eyes to stereoscopically view multiple parallax images (e.g., nine parallax images) taken from a plurality of viewpoints with use of a light direction controller such as a lenticular lens has recently come into practical use. Note that two parallax images or nine parallax images displayed by a monitor allowing stereoscopic viewing may be generated by estimating depth information of an image taken from one viewing point and performing image processing with use of the estimated information.
Recently-commercialized monitors which allow stereoscopic viewing include an apparatus that employs a light direction controller such as a lenticular lens, which allows an observer to stereoscopically view multiple parallax images (e.g., nine parallax images) by naked eyes. Such a stereoscopic display apparatus is an apparatus which allows stereoscopic viewing with binocular parallax and also allows stereoscopic viewing with motion parallax that refers to a change in observed picture with movement of a viewpoint of an observer.
Use of a naked-eye 3D monitor allowing stereoscopic viewing by naked eyes for medical use eliminates a need for annoying glasses, e.g., even during surgery. When a naked-eye 3D monitor is used for medical use, a plurality of people may simultaneously and stereoscopically view a medical image. In particular, during surgery, a plurality of people view a naked-eye 3D monitor from different directions. For this reason, there have been developed techniques for a naked-eye 3D monitor which allow stereoscopic viewing regardless of from what angle the monitor is viewed.
It commonly happens that a medical image and an examination report are simultaneously displayed on a screen and that a doctor enters findings made through a diagnosis using the medical image into the examination report. In this case, if the medical image is displayed as a 3D image, the 3D display facilitates visual recognition of an antero-posterior positional relationship hard to be determined in two dimensions and discovery of a lesion.
However, text information such as an examination report is two-dimensional information. To display an examination report simultaneously with a medical image being displayed as a 3D image, another two-dimensional monitor has been used to display the examination report. Although a 3D monitor can display two-dimensional text information, if an eye direction changes in a lateral direction, the text information looks oblique and is hard to see.